plagiarsm

like i said on title, i test some of plagiarsm tools with the same articles, and repeat it 2 or 3 times, still showing the same result 82% unique, can i trust it?

I was using smallseotools.com/plagiarism-checker/ but I tested the quetext.com today and all my articles that are showing 0% plagiarsm on smallseotools, on quetext.com are showing a lot of percent. Now I'm confused. What should I do?